The present invention relates to internal combustion engines the working cycle of which comprises six strokes or more such as described for example in the U.S. Pat. No. 4,513,568 and in the European patent application published No. 0 104 541 or in the publication of the "Society of Automotive Engineers, Inc." entitled "The Bajulaz Cycle: A Two-Chamber Internal Combustion Engine with Increased Thermal Efficiency" in the SAE Technical Paper Series No. 860534 of February 1986.
From a practical point of view, such engines suffer the inconvenience that the clearance between rotating or oscillating portions of the engine is small which can in certain instances present problems relating to excessive friction.